Blood coagulation and inflammatory systems can be activated upon contact with a foreign surface. Although biomedical device technology has made progress, a surface that is completely biocompatible for long term use has not been achieved. The clinical means to prevent thrombosis still requires the co-administration of anti-coagulants, predominantly heparin. STS Biopolymers is developing polymer (MEDI-COAT/TM) coatings containing heparin complexes for rendering vascular catheters anti- thrombogenic for extended periods. In the Phase I portion of this project we measured the loaded amount on, the extraction rates from, and the in vitro anti-coagulant activity of heparin from prototype MEDI-COAT/TM coated catheters. A MEDI-COAT/TM catheter demonstrating prolonged heparin extraction was then evaluated in vitro. We will continue the product development of an anti-thrombogenic catheter in Phase II by further characterizing and optimizing the MEDI- COAT/TM technology used in Phase I. Polymer coating formulations will be modified to achieve optimal coating structure and performance. Solution stability coating morphology, and coating integrity will be evaluated.. For prototype formulations, elution testing in vitro and in vivo will determine the performance effects of formulation changes. Catheter coating parameters affecting product quality will also be optimized. MEDI-COAT/TM coatings with sustained anti-coagulant activity will proceed to clinical evaluation in Phase III. PROPOSED COMMERCIAL APPLICATIONS: Medical devices and procedures that would benefit from anti- thrombogenic MEDI-COAT/TM system include in dwelling catheters, coronary bypass oxygnators, coronary stents and hemodialysis.